In addition to what Dark Panther already mentioned, "ran down" can also indicate a direction of running (if it's downhill or perhaps if the destination is south of where you started (though not necessarily south). Also used if you're coming from a tall building and you had to go to somewhere on the street level, that would also be used. "I ran down to the post office before it closed." "The boy ran down to the piers to watch the ship come in." "Run down" can also mean to be hit by a car (or other vehicle)! :) "The woman got run down by the bus." Best, ~_~. Maidhc

ran = is the past tense of 'run' (to go quickly by moving the legs more rapidly than at a walk and in such a manner that for an instant in each step all or both feet are off the ground) "ran down"/ "run down" is to be tired. Some examples from a dictionary: 1. fatigued; weary; exhausted. 2. in a state of poor health: He was in a run-down condition from months of overwork. 3. in neglected condition; fallen into disrepair: a run-down house.

"run down" is an idiom. It has several meanings. And "run" has more meanings than you can shake as stick at. Sorry I am too exhausted to define them for you here. I suggest a nice dictionary. Good luck.